Thanks peoples.
So the Samyang is the only
TILT lens with an aperture ring that can be set manually. I was hoping for a longer focal length, preferably around 50mm.
Picky, aren't I?
I have a Canon 35/2.8 TS for FD mount that works well, and is good optically. It was (and is) way better than the Nikon 35PC, Minolta 35 and Olympus 35. In fact, optically it's pretty close to the Zeiss, and it has a larger image circle. I bought it in the early 70's and had it converted to Konica Autoreflex mount as that had a number of operational advantages over Nikon and Canon at the time. Now I use it with adapters on a Sony A7RII mostly, but it does work on Leica M. The M is just not the best body for it, in part because the throat is both small and a little bit further from the sensor plane than on the Sony, which of course is not ideal either.
The 28 Super-Angulon, either from Leica or Schneider is not that good shifted, but the biggest issue is its distortion. Almost as bad as the Pentax 28 shift.
Just in case you're considering it, the Canon 45 TSE isn't worth getting. Fortunately they're replacing it finally.
I also use Canon 24 TSE II, 17 TSE and 90 TSE. And a Mamiya 55mm/4 shift. I still have a Nikon 28PC, but that is for a Roundshot and is not that useful on a Leica or Sony.